On a day to day basis, we see customers reporting problems where streams would "stop after a period of time" or "drop out" which are determined to be caused by Wowza Media Server hitting its resource limitations. We constantly refer our customers to the Official Wowza Media Server tuning Guide which is designed for server administrators and often it is difficult to follow.
We have developed our own Wowza Media Server Tuning Script for linux which will handle the basic configurations such as upgrading the memory limit from 768MB to something more accurate to your system or upgrading the CPU limitation from 4 CPU cores to be more compatible with your high performance dual quad core system!
Check out our Wowza Tuning Script for Linux or if you are using windows, head over to our Wowza Tuning Guide for Windows Server 2003 & 2008.